Diazotype reproduction materials



June 7, 1966 J. KOSAR 3,255,007

DIAZOTYPE REPRODUCTION MATERIALS Filed March 19, 1963 FIG.I

HEAT-DEVELOPABLE TWO-COMPONENT PHOTOSENSITIVE EZTIRTT HEAT-DEVELOPABLETWO-COMPONENT PHOTO- SENSITIVE DIAZOTYPE REPRODUCTION MATERIAL IO FIG.2

TWO-COMPONENT PHOTOSENSITIVE P ECO LAYER DIAZOTYPE LAYER 23 SUPPORT 2IHEAT-DEVELOPABLE TWO-COMPONENT PHOTOSENSITIVE DIAZOTYPE REPRODUCTIONMATERIAL 2O DEVELOPING SHEET 3O EAT-DECOMPOSABLE AMIDE 32 SUPPORT 3|FIG.3

H EAT-DECOMPOSABLE AMIDE 3 2 SUPPORT 3 4 TWO-COMPONENT PH OTOSENSITIVEDIAZOTYPE LAYER 35 TWO-COMPONENT PHOTOSENSITIVE DIAZOTYPE REPRODUCTIONMATERIAL 33 INVENTOR JAROMIR KOSAR BY 6% ATTORNEY United States Patent 3255 007 DIAZOTYPE REPRonrJcTIoN MATERIALS Jaromir Kosar, Beechhurst,N.Y., assignor to Keuflfel & Esser Company, Hoboken, N.J., a corporationof New Jersey Filed Mar. 19, 1963, Ser. No. 266,230 13 Claims. (Cl.96-49) The present invention relates to diazotype reproduction materialsand to methods and means for their development, and refers moreparticularly to heat-developable diazotype reproduction materials and tomethods and means for their development.

Diazotype reproduction materials are well known and have many advantagesover other means of reproduction when considering the combined bases ofquality and cost. However, they do possess some disadvantages which areinherent in the method of development.

Two methods of development are generally used: the semi-moist method andthe dry method. In the semimoist method the exposed diazotype materialis passed through a bath of coupler and squeezed dry. In the dry method,the exposed diazotype material is passed through a chamber of gaseousammonia to effect development.

The semi-moist method of development suffers from the disadvantageousrequirements of periodic replenishment of the developer supply, removalof exhausted developer, periodic cleaning of developer container, anddeleterious effects of the liquid developer on the diazotype base whichis usually paper. The dry method has the disadvantages of requiringequipment to supply, confine, and exhaust the noxious ammonia.

Other means for developing diazotype materials have been tried but wereless practical than either the semimoist or dry methods.

Heat for example has been used to develop images on reproductionmaterials but they remained heat-sensitive and ultimately wereunsatisfactory as copies.

In an attempt to eliminate the disadvantages of both the semi-moist andthe dry developing systems, heatdevelopment of diazotype reproductionmaterials was tried. This was feasible because exposure of a diazotypereproduction material through a master to a source of actinic radiationsdecomposes the diazonium compound in the non-image areas. Consequently,these areas cannot develop and the diazotype reproduction material ineffect is fixed or stabilized during exposure. The latent image couldthen be developed by some developing agent in the sensitized layer, in aseparate layer, or in a separate support.

For example, Dieterle in U.S. Patent 2,228,562 relates to a developingsheet treated with a heat-decomposable ammonia compound. Placed incontact with an exposed diazotype reproduction material and heated, thedeveloping sheet liberated ammonia vapors which developed the latentimage. The ammonia compounds, however, had very poor shelf-life andconsequently, their practical use was limited.

Barde in U.S. Patent 2,313,288 incorporated urea into a layer with adiazoic that formed its own coupler as a photolytic decompositionproduct. Heat decomposed the urea to liberate ammonia vapors which thenneutralized the acid formed during coupling. Morrison in U.S. Patent2,732,299, on the other hand, incorporated urea into a separate stratumon the diazotype reproduction material to serve as the source ofheat-liberated ammonia.

Greig in U.S. Patent 2,691,587; Marron in U.S. Patent 2,774,669; andBenbrook in U.S. Patent 2,789,904 all relate to developing sheetscontaining either the coupler or the source of heat-liberated alkali.

Kendall et al. in British Patent 815,005 relates to multilayer diazotypereproduction material which comprised M 3,255,007 Ice Patented June 7,1966 a support bearing a coupler layer, a fusible barrier layer, and adiazo layer.

Botkin in U.S. Patent 2,727,820 relates to an improvement in theproduction of photographic prints by the diazotype process whereincarboxamides were included in the photosensitive diazo layer to act asdeveloping aids when the diazotype reproduction material was developedin a conventional ammonia developing machine.

The system of using developing sheets containing a source ofheat-liberated alkali avoided the disadvantages of liquid developers andof gaseous ammonia, but it introduced the inconveninece of a two-sheetsystem. The developing sheet had to be placed in uniform contact withthe exposed sensitized surface of the diazo-type reproduction materialto form a two-ply assembly which was then heated to effect development.The developing sheet was then separated from the reproduction materialand set aside.

The major advantage of a developing sheet was the isolation of acritical ingredient until needed.

Isolation of the critical ingredient of the system could also beaccomplished by precoatings or multilayer coatings. This would overcomethe objection to the twosheet system, but at the expense of increasedcost and increased technical difiiculty.

The simplest system was to coat all ingredients onto one support fromone solution in one layer in one operation. One requirement was thatboth the solution and the coated layer be stabilized to preventpremature coupling of the diazo compound and the coupler.

The present invention provides heat-developable twocomponentlight-sensitive diazotype reproduction materials,'systems, and methods,which avoid the use of liquid developers and gaseous ammonia and whichare stable against further development. The invention is adaptable tothe developing sheet system, the precoat or multilayer system, and tothe single layer coating system.

One object of the present invention is to provide a heat-developablediazotype reproduction material, system, and method which does nothavethe disadvantages of prior art.

Another object is to provide a heat-developable diazotype reproductionmaterial, system, and method which does not require the use of liquiddevelopers or gaseous ammonia for development.

Another object is to provide a heat-developable diazotype reproductionmaterial which is stable against further color development.

Another object is to provide a heat-developable diazotype reproductionmaterial which is inexpensive and which gives good quality diazoreproductions.

Another object is to provide a heat-sensitive developing sheet for thethermal development of diazotype reproduction materials.

Another object is to provide a system which is adaptable to thetwo-sheet, the precoat, and the single layer systems of thermaldevelopment of diazotype reproduction materials. I

Other objects of the present invention will become apparent in thecourse of the following specification.

In the present invention, thermally decomposable sources of alkali areused as developing agents for the diazotype reproduction material. Thesesources of alkali are organic nitrogen compounds which may be classifiedas amides. Depending upon their chemical nature, they may be used in thesensitized layer, in a precoated layer, or in a separate developingsheet. Thus these amides can be used in at least three diazotypereproduction systems.

The amides of the present invention are decomposed at elevatedtemperatures when it is desired to release ammonia. This raises thealkalinity of the sensitized layer and allows coupling to occur and thusrenders the latent image visible.

Some of the amides found to be suitable for .the present invention arethose derived from monobasic staturated acids, monobasic unsaturated,acids, aromatic carboxylic acids, aromatic hydroxy acids, saturateddibasic acids, and aromatic dibasic acids. These amides have the generalformula:

Ri-( 'i1TTR2 R3 Where R is hydrogen, alkyl, substituted alkyl, alkylene,substituted alkylene, amidated alkyl, aryl, substituted aryl, amidatedaryl, a heterocyclic ring or a polymeric chain, and

Where R and R may be the same or different and represent hydrogen,alkyl, substituted alkyl, amidated alkyl, aryl, or substituted aryl.

Some sub-generic structural formulas are the following:

nH2...1 NH

Where n is 0, 1, 2, 3, 4, 5, 8, or 17 R CH CONH where R; is OC6H C H orCO-NI- I CH2=(|3OONH2 where R is H, or CH R5G0lTIOiH5 CsHs where R is H,or CH RC H CONH where R is H, CH N0 NH CONH or OH R CONH where R 8 is aheterocyclic five-membered or six-membered ring l (iJOJ where there isat least one amido group per monomer unit for this amidated polymericchain. n is preferably approximately 560.

Amides are derived from carboxylic acids by replacing the OH group withan NH group or NR R group where R and R may be hydrogen, alkyl, or aryl.The amides are generally solids at room temperatures; the

lower molecular weight amides being readily soluble in Water, while thehigher molecular weightamides are almost insoluble in water.

By heating in the presence of acids, the amides are hydrolyzed tocarboxylic acids with consequent liberation of alkaline vapors. Thesealkaline vapors are utilized to develop the exposed diazotypereproduction material. The presence of acid is not required foroperation of the invention. This is demonstrated by Example 17 andothers.

Combinations of diazonium compounds and couplers that are suitable forthe conventional d-ry developing diazotype reproduction materials can beemployed in the present invention. Examples of the diazonium compoundsare the zinc chloride and the boron trifluoride stabilized salts ofp-dialkylamino benzene diazonium chlorides. These compounds are used inconcentrations ranging from 1.5 to 10% of the sensitizing solution, andthey can be used singly or in combinations.

Some suitable couplers are phenols and naphthols, such asphloroglucinol, resorcinol, alpha-naphthol, betanaphthol, and2,3-dihydroxynaphthalene-6 sulfonic acid (sodium salt). These couplersmay be used singly or in ombination to vary the color.

The coating solution and the senstized layer can also contain variousother chemicals commonly used in the preparation of light-sensitivediazotype reproduction materials. These include stabilizing acids,anti-oxidants, hygroscopic agents, wetting agents, and imageintensifiers.

Acids that can be used are tartaric acid, citric acid, acetic acid,trichloroacetic acid, and 1,3,6-naphthlenetrisulfonic acid or its sodiumsalt.

Thiourea and allyl isothiocyanate are commonly used anti-oxidants.

The sensitizing solution and sensitized layer may further containhygroscopic agents such as glycerine, ethylene glycol, or the like;wetting agents such as saponin and lauryl sulfonates; and imageintensifiers such as zinc chloride and nickel sulfate.

' The coating solution is applied in a conventional manner to a suitablesupport, the excess removed, and the coating dried. Suitable supportsinclude not only those types of papers such as ordinary pulp paper, ragpaper, and document paper, but also starch filled cloth, felt,saponified cellulose acetate film, transparent cellulosic material suchas cellophane, and the like. In the drawings:

FIGURE 1 is a sectional view of a heat-developable two-componentphotosensitive diazotype reproduction material 10 of the presentinvention comprising a support 11 and a heat-developable two-componentphotosensitive diazo-type layer 12 coated on said support;

FIGURE 2 is a sectional View of a heat-developable two-componentphotosensitive diazotype reproduction material 20 of the presentinvention comprising a support 21, a precoat layer 22 coated on saidsupport, and a two-component photosensitive diazotype layer- 23 coatedover said precoat layer on said support; and

FIGURE 3 is a sectional view of a developingsheet 30 comprising asupport 31 and a heat-decomposable amide 32 impregnated in support 31,in juxtaposition with a two-component photosensitive diazotypereproduction material 33 comprising a support 34 and a two-componentphotosensitive diazotype layer 35 coated on support 34.

One method of the present invention for the preparation of aheat-developable reproduction material is to first treat a supportmaterial with a solution of an amide. After drying, the same support istreated on the same side or on the opposite side with a sensitizingsolution containing as major ingredients: a diazonium compound, acoupler, and where desired, a stabilizing acid. After drying, thesensitized support is ready for use. The sensitized support is exposedthrough a master to actinic radiations and is then developed by heat'inthe range between the decomposition temperature of the amide and thescorching temperature of the support material. The heat-activatedliberation of alkaline vapors then causes the image to develop.

The preparation and'use of a heat-developable twocomponentphotosensitive diazotype reproduction material precoated with an amideof the present invention is illustrated in Example 1.

In another method of preparation of the present invention, the amide isincorporated with the photosensitive diazonium compound, a coupler, andwhere desired, a stabilizing acid in a sensitizing solution which isapplied to a support and then dried. The sensitized support can then beexposed through a master to actinic radiations. After exposure, heat isapplied to the sup port. The temperature is preferably in the rangebetween the decomposition temperature of the amide and the scorchingtemperature of the support mate-rial. This method of preparation isillustrated in Example 2.

A developing sheet was prepared by impregnating a support with asolution of an amide in an appropriate solvent. The solvent was thenremoved by drying. The developing sheet was then used to develop anexposed two-component photosensitive diazotype reproduction material bymaking face-to-face contact with the exposed sensitized surface of thediazotype material and subjecting the assembly to heat in the rangebetween the decomposition temperature of the amide and the scorchingtemperature of the diazotype support. Alkaline vapors were liberated toeffect development of the latent image. The preparation and use of adeveloping sheet utilizing an amide of the present invention isillustrated in Example 3.

As an alternative procedure, the alkali-liberating agent may beincorporated into the pulp or raw material used to manufacture thesupport in suitable proportions to obtain the desired results.

The developing temperature range was determined by two factors: thefirst was the decomposition temperature of the thermally decomposableamide, and the second was the scorching temperature of the support. Thedecomposition temperature of the thermally decomposable amide isaffected by the presence of other chemicals in the system. The presenceof a good source of hydrogen ions favors decomposition by hydrolysis.

The following examples further illustrate the present invention and arenot intended to restrict or limit the scope of the invention.

EXAMPLES Example 1.30 grams of acrylamide were dissolved in 150milliliters of water and were coated onto a paper The coating was driedto produce a preooated and sensitized diazotype reproduction material.This was exposed through a master to actinic radiations and developed bysubjecting the reproduction material to 150 C. for a few seconds. Theheat liberated alkaline vapors from the amide and allowed the diazoniumcompound and the coupler to form a blue dye image corresponding to themaster image.

No liquid developer or gaseous ammonia was required for development. Inaddition the developed reproduction material was stable against furtherdye formation under the influence of heat. This precoating system wasparticularly suitable for amides which were not watersoluble or whichwere not compatible with the chemicals in the sensitizing solution.

Example 2.-A sensitizing solution according to the following formula wasprepared and coated on a conventional silica-sized diazotype papersupport:

Water ml 4500 Acrylamide g 900 Tartaric acid g 15 Trichloroacetic acid g150 Sodium salt of 1,3,6-naphthalene trisulfonic acid g 180p-Dimethyl-amino' benzene diazonium chloride, zinc chloride salt g 120Sodium salt of 2,3-dihydroxynaphthalene-6-sulfonic acid g 150 Thiourea g210 Zinc chloride g 120 ing to the master image.

This system and method was preferred whenever the water solubility andthe chemical compatibility of the amide with the other chemicalspermitted incorporation into a single solution. Diazonium compoundsother than "p-dimethylaimino benzene diazonium chloride can be usede.-g., p-diethylam-ino benzene diazonium chloride, andN-ethyl-N-(Z-hydroxyethyl)-p-amino benzene diazonium chloride were alsoused. Another coupler such as phloroglucinol was also used.

Example 3.20 grams of acrylamide were dissolved in ml. of ethyl alcohol.This solution was used to impregnate a porous paper support. Afterdrying, a developing sheet for the heat-development of exposedtwo-component diazotype reproduction mate-rials was produced. On aseparate paper support the sensitizing solution of Example 1 was appliedand dried. This was ex- !posed through a master to actinic radiationsand developed by making face-to-face contact with 'the' developing sheetand subjecting the whole assembly to C. for 5 seconds. A blue dye imagecorresponding to the master image was produced without benefit of liquiddeveloper or gaseous ammonia. The print was stable against any furtherdye formation due to the application of heat.

This system was ideal for amides which were not compatible with thechemicals of the sensitizing solution since isolation was complete. Inprinciple, this isolation can also be achieved by the multilayer systemdescribed in British Patent 815,005 and by microencapsulation of thedeveloping agent or the coupler.

These first three examples demonstrate the fact that an amide can beused in three different systems as the source of alkali for theheat-development of diazotype reproduction materials.

Example 4 .--The following sensitizing solution was prepared and coatedon a support. After the coating was dried, the sensitized support wasexposed to actinic radiation through a master and developed bysubjecting it to heat. The color of the image was blue.

Water ml 150 Sodium salt of 1,2,6-naphthalene trisulfonic acid g 6Trichlor'oacetic acid g 5 p-Dimethylamino benzene diazonium chloride,zinc chloride salt g 4 Sodium salt of2,3-dihydroxynaphthalene-6-sulfonic acid g 5 Thiourea g 7 Zinc chlorideg Formamide g 10 Example 5.A coating of the following diazo sensitizingsolution was applied to a paper support:

An absorbent sheet, was soaked with the following solution:

Ethyl alcohol ml 100 N,N-diiphenylforrnamide a g 10 Trichloroacetic acidg 5 After drying, the developing sheet was brought into uniform contactwith the sensitized paper which had been exposed through a master toactinic radiations. The assembly of developing sheet and the diazosensitized paper was then heated at 150 C. for seconds to produce a blueimage on the diazo sensitized paper corresponding to the master image.

Example 6.The following sensitizing solution was coated on a supportsuitable for diazotype reproduction materials:

Water ml 150 Trisodium salt of 1,3,6-naphthalene trisulfonie acid g 6p-Dimethylamino benzene diazonium chloride, zinc chloride salt g 4Sodium salt of 2,3-dihydroxynaphthalene-6-sulfonic acid g 5 Thiourea gZinc chloride g 4 Acetamide g 30 pH adjusted to 3.4 withtrichloroacet'ic acid.

The sensitized support was then dried and exposed through a master toactinic radiation. Heat was used to develop the latent image as a bluedye image.

Example 7.-To improve storage life, trichloroacetic acid was addedaccording to the following formula:

Water ml 150 Tartaric acid g .Trisodium salt of 1,3,6-naphthalenetrisulfonic acid g 6 p-Dimethylamino benzene diazonium chloride, zincchloride salt g 4 Acetamide g 30 Sodium salt of2,3-dihydroxynaphthalene-6sulfonic acid g 5 Thiourea g 10 Zinc chlorideg 4 Trichloroacetic acid g 5.

The pH of the solution was 1.3. Storage life was improved by theaddition of trichloroacetic acid. Material stored at 115 F. and 47%relative humidity for three days still produced acceptable andsatisfactory prints. Lesser amounts of trichloroactic acid reduced thestorage life of the sensitized reproduction material.

Example 8.-The following sensitizing solution was prepared and coated ona support suitable for diazotype reproduction materials on a productionrun basis:

Water ml 4500 Tartaric acid g Trichloroacetic acid g 150 Trisodium saltof 1,3,6-naphthalene trisulfonic acid g 180 p-Dimethylamino benzenediazonium chloride, zinc chloride salt g 120 Acetamide g 900 Sodium saltof 2,3-dihydroxynaphthalene-6-sulfonic acid g 150 Thiourea g 210 Zincchloride g 120 The coating speed was 16 yards per minute within air-barpressure of 3 /2 oz. of water. The drying temperature was 180 F.

The sensitized and dried material was then exposed through a master toactinic radiation and developed by the application of heat. Thedeveloped image was blue in color and satisfactory in density.

Example 9.A support sheet was pre-coated with the following solution:

Water ml 150 Acetamide g After drying, the precoated support Wassensitized with the following sensitizing solution:

Water ml 150 Trisodium salt of 1,3,6-naphthalene trisulfonie acid g 6Trichloroacetic acid g 5 p-Dimethylamino benzene diazonium chloride,zinc chloride salt g 4 Sodium salt of2,3-dihydroxynaphthalene-6-sulfonic acid g 5 Thiourea g 7 Zinc chlorideg 4 The pH of the sensitizing solution was 1.0 After drying, thesensitized sheet was exposed through a master to actinic radiations anddeveloped by heating at 150 C. for 4 seconds. A blue image correspondingto the master image was obtained.

Example I0.An absorbent base sheet was soaked in a solution containing10 grams of acetamide in 150 ml. of ethyl alcohol and then dried toremove the alcohol to produce a developing sheet.

A paper support was sensitized with the following solution:

Water ml 150 Trisodium salt of 1,3,6-naphthalene trisulfonic acid g 6 Trichloroacetic acid g 5 p-Dimethylamino benzene diazonium chloride, zincchloride salt g 4 Sodium salt of 2,3-dihydroxynaphthalene-fi-sulfonicacid g 5 Thiourea g 7 Zinc chloride g 4 After drying, the developingsheet and the exposed sensitized support were placed in contact andheated at 150 C. for a few seconds to produce a blue image correspondingto the master image.

Example 1 1.T he following solution was prepared and coated on anabsorbent support to form a developing sheet: v

Ethyl alcohol Q ml.. 25 T-richloroacetic acid g 1 Phenoxyacetamide g 2.5

Heating this sheet in contact at 175 C. for 5 seconds with a printed butundeveloped diazotype paper such as that described in Example 10produced a brown image.

Example 12.A developing sheet prepared by coating the following solutionon an absorbent support when heated in cont-act with printed diazotypepaper as described in Example 10 caused a blue image to be produced onthe diazotype paper:

Ethyl alcohol cc Trichloroacetic acid g 3 N,N-Diphenylacetamide g 10Contact time was 6 seconds at 170 C.

Example 13.-The following solution was prepared After printing through amaster, the blue image was developed by heating for 5 seconds at C.

Example -14.-Propionamide was used in the following solution to preparea developing sheet:

Water cc 100 Trichloroacetic acid g 2 Propionamide g 5 When used todevelop a printed diazotype paper such as that described in Example 10,a blue image was obtained. Contact time was 5 seconds at 150 C.

Example 15.The following chemicals were substituted individually for thepropionamide in Example 13 with the result that the developed imageswere substantially the same as for propionamide:

n-Valeramide iso-Valer-amide n-Butyramide iso-Butyramide Example16.-Hexamide, nonanamide, and stearamide were used separately in thefollowing solution formula to prepare developing sheets:

Ethyl alcohol cc 50 Trichloroacetic acid g 1.5 Amide g 5 When thesedeveloping sheets were used to develop printed diazotype sheets preparedas described in Example 10, blue images were obtained. Contact time was5 seconds at 160 C.

Example 17.The sensitizing solution was prepared with acrylamideaccording to the following formula:

Water cc 100 p-Diethylamino benzene diazonium chloride, zinc chloridesalt g 4 2,3-dihydroxynaphthalene 6 sulfonic acid, sodium salt g 5Acrylamide g 50 This solution was coated on an absorbent support anddried. When heat-developed at 150 C. for 5 seconds a blue color wasdeveloped.

Example 18.Polyacrylamide of low molecular weight such as PAM 10 wasused in the following sensitizing solution:

This solution was coated on an absorbent support and was dried. Afterprinting with ultraviolet light through a master, the image wasdeveloped by heating the coated support at 150 C. for 5 seconds.

Example 19.-Polyacrylamide such as PAM 10 was used in the followingsolution to prepare a precoat solution:

Water cc 100 P-olyacrylamide PAM 1O g 50 Trichloroacetic acid g 10 Thissolution was coated on a support and dried. The precoated paper was thensensitized with a solution such as described in Example 1. Heattreatment after exposing the sensitized support through a masterproduced a blue dye image.

Example 20.-The same polyacrylamide solution as in Example 19 was usedto coat an absorbent support to make a developing sheet. When used as inExample 3 to develop a diazotype paper by placing it in contact with theexposed diazotype paper and heating the assembly for a few seconds at150 C., a blue image on the diazotype paper was developed.

Example 21.Hexamethylene-bis-acrylamide was used to prepare a solutionaccording to the following formula:

Ethyl alcohol cc Hexamethylene-bis-acrylamide g 10 Trichloroacetic acidg 5 This solution was used to impregnate an absorbent support. Afterdrying, this developing sheet was placed in contact with sensitized andexposed diazotype paper and heated at C. for 8 seconds. A blue image wasformed.

Example 22.--Methacrylamide was used in place of the acrylamide ofexamples 2, and 17, with the same results.

Example 23.-Malonamide was used in the following sensitizing solution tocoat a support which was then dried:

Water cc 150 Malonamide g 25 1,3,6-naphthalene trisulfonic acid,trisodium salt g 6 Tartaric acid g /2 Trichloroacetic acid g 5p-Dimethylamino benzene diazonium chloride, zinc chloride salt g 42,3-dihydroxynaphthalene 6 sulfonic acid, sodium salt g 5 Thiourea g 7Zinc chloride g 4 Development of a blue dye image after exposure wasaccomplished by heating at 180 C. for 4 seconds.

Example 24.Benzamide was used in the following solution to prepare adeveloping sheet:

Ethyl alcohol cc 100 Benzamide g 5 This solution was then used toimpregnate an absorbent support. Heating the developing sheet while itwas in contact with a diazotype paper prepared as in Example 5 resultedin development of a blue color on the diazotype sheet.

' Example 25.-The solution of Example 24 was used also as a precoatsolution. It was coated on a support, dried, and then sensitized withthe following solution on the same side:

Water cc 150 1,3,6-naphthalene trisulfonic acid, trisodium salt g- 6Tartaric acid g /2 p-Dimethylamino benzene diazonium chloride, zin

chloride salt g.'. 4 2,3,-dihydroxynaphthalene-6-sulfonic acid, sodiumsalt g 5 Thiourea g 7 Zinc chloride g 4 After exposure through a master,a blue dye image was developed by heating the exposed sheet for 5seconds at 150 C.

Example 26.p-Toluamide was used in the following solution to prepare adeveloping sheet:

Ethyl alcohol cc 50 p-Toluamide g 5 Trichloroacetic acid g 1.5

The developing sheet was used to develop diazotype paper prepared as inExample 5. A blue color was developed by heating the developing sheet incontact with the diazotype paper for a few second at C.

Example 27.p-Nit-robe'nzamide was used inthe following solution toprepare a developing sheet:

Ethyl alcohol cc 25 p-Nitrobenzamide g 2.5 Trichloroacetic acid g 1.0

11 1 This developing sheet was used to develop a red-brown dye color inthe same manner as in Example 26.

Example 28.Anthranilamide Was used in the follow-' ing solution toprepare a develop-ing sheet:

Ethyl alcohol cc 100 Anthranilamide g 10 Trichloroacetic acid g Thissolution was coated on a support to make a developing sheet which thenwas used to develop a diazotype paper as described in Example 5 toproduce a blue dye image.

Example 29 .Anthranilamide was also used in the following sensitizingsolution:

exposed sensitized sheet at 160 C. for 6 seconds produced a blue dyeimage.

Example 30.Phthalamide was used to make a developing sheet by coating asupport with the following solution:

Ethyl alcohol cc 100 Phthalamide g 5 Trichloroacetic acid g 2.5

Placing this developing sheet in contact with a printed diazotype paperand subjecting the assembly to heat at 175 C. for several secondsproduced a blue image.

Example 31.Salicylamide was used in a developing sheet prepared bycoating a support with the following solution:

Ethyl alcohol cc 100 Salicylamide g 5 The developing sheet was used todevelop a blue dye image as in Examples 5 and 30.

Example 32.Salicylamide was also used in a precoat layer by coating asupport with the following solution:

Ethyl alcohol cc 150 Salicylamide g 10 The precoated support was thensensitized as in Example 9. After exposure through a master to actinicradiations, a blue color was developed by heating ,the sensitizedprecoated support for 5 seconds at 150 C.

Example 33.-2-furamide was used in the following solution to coat asupport to make a developing sheet:

Ethyl alcohol 'cc 50 Z-furamide g 5 Trichloroacetic acid g 1.5

This developing sheet was used at 175 C. for 4 seconds to developprinted diazotype paper as described in Example 5.

Example 34.-N-Methylacetamide was used to prepare a developing sheet byimpregnating an absorbent support with the following solution:

Ethyl alcohol cc 25.0 N-methylacetamide g 2.5 Trichloroacetic acid g 1.0

After drying, this developing sheet was used to develop exposeddiazotype paper prepared asin Example 5 by placing the two sheets incontact and heating them at 165 C. for 7 seconds to obtain a blue color.

12 Example 35.Example 34 was repeated with 2-phenylacetamide in place ofN-methylacetamide. After following the same procedure, a blue greenimage was obtained. Example 36.Nicotinamide was used in the followingsolution to impregnate an absorbent support to make a developing sheet:

Water cc 50 Nicotinamide g 5 This sheet was then dried and used todevelop an exposed diazotype paper by placing it in contact with theexposed diazotype paper and heating the assembly at C. for 6 seconds toobtain a colored image.

Example 37.-A support was precoated with the following solution:

Water cc 50 Nicotinamide a g- 5 Trichloroacetic acid g 2 After drying,the precoated support was sensitized with the following solution:

Water cc 150 Tartaric acid g /2 1,3,6-naphthalene trisulfonic acid,trisodium salt g 6 p-dimethylamino benzene diazonium chloride, zincchloride salt g 4 2,3-dihydroxynaphthalene-6-sulfonic acid, sodium saltg 5 Thiourea g 7 Zinc chloride g 4 After drying, the sensitized supportwas exposed through a master to actinic radiations and then developed byheating at C. for 5 seconds. A blue-black image was obtained.

It is apparent that the described examples are capable of manymodifications and variation within the scope of the present invention.All such modifications and variations are to be included within thescope of the present invention.

What is claimed is:

1. A process for making a diazo reproduction of an image, whichcomprises the steps of:

exposing a diazo sheet to imagewise actinic radiation,

said sheet comprising a support resistant to the scorching effects ofheat at the conditions of development and a photosensitive diazoniumcompound, a coupler therefor, and a thermally decomposablealkali-liberating amide on said support, said amide having the generalformula:

where R is a member selected from the group consisting of hydrogen,alkyl, alkylene, aryl, and amidated polymer having a molecular weight ofabout 40,000, and R and R are members selected from the group consistingof hydrogen, alkyl and aryl; and heating said exposed sheet at atemperature between the decomposition temperature of the amide and thescorching temperature of the support to liberate alkali and produce adye image on the diazo sheet.

2. A process in accordance with claim 1 in which said amide is watersoluble and is intimately admixed with said diazo layer.

3. A process in accordance with claim 2 in which said amide isacrylamide. I

4. A process in accordance with claim 2 in which said amide isacetamide.

5. A process in accordance with claim 2 in which said amide ispolyacrylamide with a molecular weight of about 40,000. 1

6. A process in accordance with claim 2 in which said amide ismalonamide.

7. A process in accordance with claim 2 in which said amide isanthranilamide.

8. A process in accordance with claim 1 in which said amide is coated onsaid support between said support and said diazo layer.

9. A process in accordance with claim 8 in which said amide isacrylamide.

10. A process in accordance with claim 8 in which said amide isacetamide.

11. A process in accordance with claim 8 in which said amide ispolyacrylamide with a molecular Weight of about 40,000,

12. A process in accordance with claim 8 in which said amide isbenzamide.

13. A process in accordance with claim 8 in which said amide issalicylamide.

References Cited by the Examiner UNITED STATES PATENTS 2,047,217 7/ 1936McQueen et a1. 2,358,871 9/1944 Maxwell. 2,653,091 9/1953 Greig 9649 1 42,683,088 7/1954 Reynolds 117 154 X 2,687,958 8/1954 Neugebauer et a1.9693 X 2,727,820 12/1955 Botkin et a1. 9649 2,732,299 1/ 1956 Morrison9649 2,774,669 12/ 1956 Marron et a1. 9649 2,786,807 3/ 1957 Schwartz.

FOREIGN PATENTS 519,408 12/ 1955 Canada.

564,915 10/ 1958 Canada. 1,249,913 11/1960 France.

816,601 7/ 1961 Great Britain.

127,464 2/ 1950 Sweden.

OTHER REFERENCES Degering: Outline of Organic Nitrogen Compounds, 1950,University Lithoprinters, Upsilanti, Michigan, pp. 408-411. Kosar:Photographic Science & Engineering, vol. 5,

20 No. 4, July-August 1961, pages 239-243.

J. TRAVIS BROWN, Acting Primary Examiner.

NORMAN G. TORCHIN, Examiner.

1. A PROCESS FOR MAKING A DIAZO REPRODUCTION OF AN IMAGE, WHICHCOMPRISES THE STEPS OF: EXPOSING A DIAZO SHEET TO IMAGEWISE ACTINNICRADITION, SAID SHEET COMPRISING A SUPPORT RESISTANT TO THE SCORCHINGEFFECTS OF HEAT AT THE CONDITONS OF DEVELOPMENT AND A PHOTOSENSITIVEDIAZONIUM COMPOUND, A COUPLER THEREFOR, AND A THERMALY DECOMPOSABLEALKALI-LIBERATING AMIDE ON SAID SUPPORT, SAID AMIDE HAVING THE GENERALFORMULA: